Circuit substrates, especially active matrix substrates, have been widely used for active matrix display devices such as liquid crystal display devices and electroluminescence (EL) display devices. In a conventional circuit substrate used for liquid crystal display devices, for example, thin film transistor (TFT) elements are arranged at intersections of multiple gate lines and multiple source lines arranged on the substrate. By the switching function of the TFT elements, image signals are appropriately transmitted to the pixel (electrode) portions connected to the TFT elements.
Here, signal transfer may not succeed when the conductive components are not appropriately formed or damaged to break the conductive lines. From the viewpoint of increasing the yield, circuit substrates desired in various fields are those capable of making suitable repairs by forming new signal transfer routes substitutable for the broken sites with use of components such as repair lines, if necessary.
A conventional liquid crystal display device capable of repairing defects such as breakage of conductive lines is disclosed in, for example, Patent Literature 1. The liquid crystal display device includes: gate bus lines; first storage capacitor bus lines extending along the gate bus lines; data bus lines crossing the gate bus lines; and second storage capacitor bus lines that extend along the data bus lines and are electrically connected to the first storage capacitor bus lines. The first storage capacitor bus lines are formed by using the same conductive film as the gate bus lines or data bus lines. The second storage capacitor bus lines are formed by using the same conductive film as the gate bus lines or data bus lines.
Also, Patent Literature documents 2 to 4, for example, disclose an active matrix substrate and an active matrix liquid crystal display device which are similarly capable of repairing broken conductive lines.